The Visual Editor is a graphical representation of all nodes and peripherals for the active devicetree file in the selected build context. It is divided into Peripherals and Pins Views, which let you inspect and modify node properties and pin assignments.
For information about most common actions that you can do in the editor, see How to work with Devicetree Visual Editor.
Note
The Visual Editor is a tab in Visual Studio Code's Editor. The extension opens one global instance of the Virtual Editor, which aligns with the contents of the active devicetree file. The active context can change when switching tabs if the nrfconnect.activeAppFollowActiveEditor setting is set to true.